Beer commonly comes in 8oz cans. 8oz is about 237mL, 3% of which is about 7mL. I would absolutely say that 7mL of beer is going to do jack shit.
The experience of the subject is linked directly to obvious perception. If it isn't affecting perception, it's not affecting experience! It could affect other things, like your liver or whatever, but it really does need to affect your perception in order to have the benefits people claim microdosing has, which are all linked to moment-to-moment experience.
I was basing my analogy on the idea that a standard dose of beer, for someone drinking beer, is probably 2 12 oz. bottles of beer.
"If it isn't affecting perception, it's not affecting experience!" I think this is the main point on which we disagree. I'm curious why you assert this so strongly.
If we agree that there is an effect on the nervous system, then the question is, at what point does that effect "matter". And you are saying that it only matters at the point that the subject can detect the shift in their own perception from baseline. You also argue that any purported benefits of the substance are only realized as a result of the detection in this change of state.
I can think of a few examples of cases where we would not be consciously aware of a change from baseline, but would effect our experience. Do you need to be aware of your change from baseline for the painkilling and pleasantness of endorphins released after a mild walk to have an effect? Do you need to be aware of your own difference from psychological baseline for the little bit adrenaline released before an important meeting to have an effect on your alertness?
Our recognition of our own perception is a fallible signal detector. There can be effects on the nervous system that have effects on other systems, regardless of whether the conscious mind detects a signal.
And if you agree with me so far, then the question is if the effect on the nervous system and in turn its effects on other internal systems has any therapeutic effect. That's a different discussion, I reckon. But unless a requirement of all the purported therapeutic effect is that the subject has consciously observed their altered perception, then it is possible for there to be an effect on people's lives from sub-perceptual doses of chemicals. (for example: non-psychoactive drugs, heavy metals, viruses, etc.)
The experience of the subject is linked directly to obvious perception. If it isn't affecting perception, it's not affecting experience! It could affect other things, like your liver or whatever, but it really does need to affect your perception in order to have the benefits people claim microdosing has, which are all linked to moment-to-moment experience.